Self-thawing trap



March 25, 1930. H, D. GREGORY SELF' THAWING TRAP Filed July 22. 1927 Patented Mar. 25, 1930 HAROLD n. GREGORY, F CAMDEN, NEW" JERSEY SELF-TI-IAVJING TRAP Application filed Zfuly 22,

This invention relates to improvements in traps of the type more particularly adapted for use in the return lines of vapor orsteam heating systems. I r

A trapof the character referred to, such, for example, as is shown and described in Patent No. 1,575,862 of March 9,1926, to Lewis F. Ostrander, is commonly referred to as a return fitting, and isconnected in the .1 return line to the boiler at one end of the radiator, and permits ready flow ofcondensate from the latter back to the boiler, the device being provided with a vent or aperture to permit the radiator to be freed quickly of air. A suitable check valve is generally embodied in the trap and is arranged to close upon decrease in the pressure in the radiator to apoint below atmospheric to prevent air orwater, or both air and water, from entering the radiator when such a condition exists. When these traps of the type constructed heretofore are used in heating systems for churches, schools or other'buildings which are heated intermittently and are located in are prevalent,'the condensate remaining in the traps freezes when the boiler'is shut down, which condition, upon subsequent firing of theboiler, causes rapid condensation and freezing of the vapor or steam at the trap ner. In systems where there are a substantial number of radiators, some 'of which are that this thawing out operation is accom- 'plished only with considerable trouble and loss of time. For the purpose of eliminating this difficulty, it has been proposed to place.

a jacket around the trap and connect the same in the vapor supply line leading from the boiler to the usual valve controlling the flow of vapor or steam to the 'radiator, the action being that when the boiler is fired the vapor or steam,on its way to the radiator boiler to such valves.

climateswhere extremely low temperatures.

more or less inaccessible, it will be appreciated 7 1927. Serial No. 207,805.

valve, is caused to circulate around the trap and to thereby automatically thaw out the latter. While this construction has served its purpose, it makes necessaryadditional con- I nections and piping in the installation thereof, and for all practical purposes these jacketed traps constructed heretofore must be con-. nected to the radiators at the same ends there- 7 of to which the vapor or steam supplyvalves are connected to permit of connection of the 6G jacket in the supply line leading from the In this connection, it is important to note that when the length of a radiator eXeceeds three times its height it is desirable, in order to obtain the best results, to connect the trap to the end of the radiator oppositethat to which the vapor or steam supply valve is connected. lhe jacketed trapsreferred' to, furthermore, necessitate substantial increase in the dimensions and weight of the trap, as well as increase in the cost of manufacture thereof over those, constructed heretofore. ,1

One 'of the objects, of the present inven-, tion, therefore, is to provide an improved trap of the character referred to which is so constructed as to permit the radiator to be freed quickly of air under conditions when the confined condensate in the trap has frozen solid and to provide a passage for relatively warm condensate or possibly excess vapor or steam issuingfrom the radiator and to direct thesame through the trap in such wise that the latteris completely thawed out before ice can accumulate to sealthe'air vent and prevent furth'er flow of vapor or steam, as in constructions used heretofore, and wherein the trap may have the same external appearance and dimensions as those constructed heretofore, such as the Ostrander trap or re- 5 turn fitting referred to, and which may be installed or connected in the same manner as the latter and without the necessity of additional piping and connections, thereby permitting, when desirable, connection of the trap at the end of a radiator opposite that to which the vapor or steam supply valve is connected.

Another object is to provide an improved trap of the character referred to which has the advantages of traps such as the Ostrander trap referred to as regards adaptability, ease of installation and cost of manufacture,

' as well as the advantage of the acketed trap referred to as regards the automatic thawing out of the frozen condensate upon firing or starting up of the boiler.

Other objects and advantages will hereinafter appear.

In accordance with the present invention, a trap of the character referred to is provide-d interiorly thereof with a condensate and vapor or steam passage extending through the trap and communicating directly at one end thereof with the radiator and being provided at its other end with the usual air Vent referred to whereby any relatively warm condensate or excess vapor or steam in passing from the radiator after the air has been freed therefrom is caused to circulate through the frozen condensate in the trap before it reaches the air vent on its way back to the boiler by way of the return line.

For the'purpose of illustrating the invention, one embodiment thereof is shown in the drawings, in which Figure 1 is a central, vertical and longitudinal sectional view through a trap embodying the present improvements;

Figs. 2, 3,4, 5, 6 and 7 are sectional views, the sections being taken on the lines 22, 33, 4 l, 55, 66 and 77, respectively, in Figure 1;

Fig. 8 is a diagrammatic, perspective view of a vapor heating system, illustrating the manner in which traps made in accordance with the present inventionmay be embodied v therein Fig. 9 is an enlarged elevational view of a radiator, showing the improved trap connected thereto; and

Figs. 3 and 6 are views similar to Figs. 3 and 6, respectively, showing a modification.

Referring to Fig. 8, the boiler 10 for generating vapor or steam is connected through the usual supply line 11 and branch lines 12 leading therefrom to the radiators or heating elements 13, 1 1- and 15, the flow of vapor or steam into the latter being controlled in the usual manner by suitable supply valves 16. The supply line 11 leads back to the boiler,

as shown, and is connected thereto at a point below the water level therein. The improved traps or so-calle-d return fittings, designated generally by the reference numeral 17, are connected to the radiators at their lower ends and to the branch pipes 18 connected to the boiler-return line 19 which is, in turn, connected to the boiler at a point below the water level therein. An automatic thermal valve,

desi nated 'enerall b the reference numeral 20, and which may be of the general type such as is shown and described in Patent No. 1,291,099 of January 1a, 1919, to Lewis F. Ostrander, may be connected in the return line as shown, this valve operating in the well known manner to permit escape of air from the return line to the atmosphere and return of condensate and excess vapor or steam to the boiler, while preventing escape of such excess vapor or steam to the atmosphere, a suitable check valve 21 being connected as shown and arranged to open toward the boiler.

Referring now more particularly to Figs. 1 to 7, the trap 17 is provided with the inlet opening 22 connected to the radiator by the nipple 23 and union 24, the outlet opening 25 connected to the boiler return line through the branch pipe 18, and the well 26 interposed between these openings, the trap being provided at the outlet opening thereof with the hexagonal boss 27 for receiving a wrench for screwing the trap tightly on the adjacent end of branch pipe 18. The capacity of well 26 is determined in part by the dam 28 extending upwardly from the bottom or floor 29 of the trap and which is shown as being formed integrally therewith, the edge 30 of the dam terminating short of inlet opening 22 so that the normal level of the condensate in the well is slightly below this opening, as shown, for the purpose which will hereinafter appear. A wall 31, which is also shown as being formed integrally with the trap, is disposed substantially centrally of the well 26 and extends transversely of and completely across the trap from one side thereof to the other, the wall extending downwardly into the well within a relatively short distance of the trap floor 29, the upper edge 32 of the wall being disposed a substantial distance above the normal level of the condensate in well 26 for the purpose hereinafter explained, and falling short of the top or roof 33 of the trap about the same distance.

Intermediate the dam 28 and wall 31 are the vertically disposed, parallel, spaced partitions 34 extending longitudinally of the trap and being equal in height to wall 31, the partitions being spaced from the sides of the trap, as more clearly shown in Figs. 3 and 6, and merging with wall 31 and dam 28, the upper ends 35 of the partitions extending laterally outwardly therefrom and merging with the sides of the trap, as more clearly shown in Fig. 3. The central portion 36 of dam 28 extends upwardly above the edge 30 thereof and merges with the top 33 of the trap and also merges with and connects the adjacent edges of partitions 34, this construction providing the openings 37 which permit the condensate in well 26 to spill over the edge 30 of dam 28 and to then pass downwardly throughoutlet opening 25 and thence back to boiler 10 by way of pipe 18 and the return line 19.

The partitions 34; below the edge 30'of dam 28 are extended beyond the latter to the'right, as viewed in Fig. l, and merge with the end wall 38 of the trap, as more clearly shown in Fig. 6, the top edges of these extended por tions of partitions 34 being connected by the top partition 39 which also merges with end wall 38, as well as with the lower edge of the dam portion 36, as more clearly shown in Fig. 1. The lower edges of wall 31 and partitions 34 are connected by a bottom partition 40 merging also with end wall 38 and being provided with a screw-threaded opening or aperture 41 coaxial with outlet opening 25 and providing an air vent for the radiator and permitting discharge of condensate and excess vapor or steam from the latter in the manner and for the purpose hereinafter explained. To obtain the best results, and to cause all the radiators to be freed of air at substantially the same time, it is desirable that the aperture41 be adjusted for each individual radiator, the size of the aperture for a particular radiator being. governed by the size and location thereof, and 'to this end the size of the aperture is made standard and a screw or plug 42 threaded into the lat terand provided with an aperture 43 of a size best suited for this particular radiator; Similar screws with apertures varying in size may thus be provided and selected for each individualradiator in accordance with its size and location, the trap itself, however, being made standard for all sizes of radiators. The top partition 39 is provided on its upper surface with a boss 44 provided with an aperture 45 located coaxial with the opening or aperture 41 to facilitate drilling of these apertures by inserting into outlet opening 25 a drill of the proper gauge for aperture 45 and drilling through both partitions 40 and 39 and by then employing another drill of the proper gauge for aperture 41 and drilling through partition 40 only. i i a A ball check valve 46v is arranged to seat over the adjacent end of nipple 23 by a movement toward radiator 15, the valve being guided on suitable ribs 47 which may be formed integrally with the trap. The ribs or guides 47 keep valve 46 clear, under normal conditions, of condensate flowing from the radiator through nipple 23 into well 26. The location of the top 30 of dam 28 provides that the normal level of condensate in well 26 is below valve 46 and its guiding ribs 47, as shown, the latter being inclined downwardly slightly to the right, as viewedin Fig. 1, so

that the valve is biased slightly to open position under the action of gravity. Upon decrease in the pressure in the radiator to a point below atmospheric, valve 46 closesto revent the; entrance of air or condensate, or both, from entering the radiator by way of the trap. The upper end of wall 31 provides a stop for valve 46 to limit opening movement thereof, as shown.

A partition 48 extends upwardly arelastantially coextensive with well26 andis partitioned therefrom, the upper endof the passage being open anddisposed a substantial distance above the normal level of the'condensate in the well toreceive air and any excess vapor or steam issuing from the radiatorand passing into the inlet opening 22 of the trap, the other end of passage 50 communicating with the trap outlet opening 25 and return line 18 through apertures 43and 45;

The single means or plug 51 is threaded upwardly through the trap bottom 29 and partition 40, as more clearly shown in Figs.

1 and 3, and maybe removed for the purpose of cleaning well '26 and passage 50.

-, The operation of theimproved trap will now be explained, for which purpose it will be assumed that the condensate 49 and that in Well 26 are frozen solid,and that the most adverse temperature conditions prevail.

Upon firing of boiler 10, any air: in radiator 15 will escape therefrom through nipple 23, passage 50 and apertures 43 and 45, vapor or steamthen being permitted to rise freely through the supply line 11 and branch I pipe 12, some of the vapor or steam condensing due to the extremely low temperature of line 11 and pipe 12 and returning to the boiler as condensate, the remainder "passing through valve 16 into theradiator. Upon passing into the radiator the vapor or steam will be chilled due to the low temperature of the latter, and condense, the condensate dropping to the bottom of the radiator and freezing. This action will reoccur until the temperature of the radiator is raised to such a point above freezingthat the condensate accumulating in the bottom of the radiator will not freeze, but, on the contrary, will be relatively warm, and will accumulate in the radiator up to a level determined by'the top 32 of wall 31, at which time the relatively warm condensate Will begin to spill over the top 32 of wall 31 and trickle down along the interior sides of wall 31 and partitions 34 into passage 50 from which it will be discharged through aperture-43 into outletopening 25 and return line 18. Upon continued supply of vapor or steam to the radiator, the

temperature of theradiator will be Q further raised to such a point that only part of the Vapor orsteam will condense, the excess amount passing through nipple 23 into the trap and through passage 50, from which it will discharge into outlet opening 25 and return line 18 by way of aperture 43 or 45, or both these apertures. This flow of relatively warm condensate and excess vapor or steam through passage 50 will impart heat to wall 31 and partitions 34, this heat being conducted through the latter to the frozen condensate in well 26 and .completely thawing out the same and thus restoring the trap to its normal working condition.

Under more favorable temperature conditions, the relatively warm condensate first flowing through passage 50 will generally be sufficient to completely thaw out well 26, as well as the condensate 49, before any excess vapor or steam begins to issue from the radiator and to flow through passage 50.

By reason of the elevated position of aper ture 45 and the boss 44 around the same, condensate is prevented from reaching or flowing through this aperture, which is therefore 7 always dry and cannot become sealed by frozen condensate. The aperture 45 acts as an emergency air vent to providefor the escape of air from the radiator in starting up the heating system in the event that aperture 43 has been sealed by frozen condensate. Aperture 45 is relatively'small as compared with .aperture43, and in selecting the screw 42 for any particular trap, the area of aperture 45 should be taken into consideration, so that the combined areas ofapertures 43 and .45 provide the proper amount of air vent opening for the trap.

Any sediment or other solid matter which condensate passing into the same, as explained .above, will settle or collect on the left side of partition 48, the latter thereby acting to prevent accumulation of such matter at the screw or plug 42 to foul the aperture 43. Vhile the provision of partition 48 is believed to be desirable for the purpose explained, it may be omitted, in which case the partition 40 will not be tapped to receive screw 51, the latter being threaded only through the trap bottom 29 and being made equal in length to substantially the thickness thereof.

The traps connected to the radiators 13 and 14 operate and are automatically thawed out in the same manner as explained above in connection with the trap connected to radiator 15.

1 If desired, the capacity of the well may be increased by further increasing the distance between the sides of the trap, as shown in the modification in Figs. 3 and 6 the well 26 therein corresponding to the well 26 in Figs. 1 to 7. The construction shown-in Figs. 3 and 6 is otherwise identical to that in Figs. 1 to 7, so that no detail description thereof is deemed necessary, the various parts of the modified construction being designated by primed numbers corresponding to like parts in Figures 1 to 7.

For the purpose of better illustrating the adaptability of the improved trap, the same has been shown in Figures 8 and 9 as being connected to the radiator 15 at the end there of opposite that to which the vapor or steam supply valve 16 is connected, while the traps associated with'the radiators 13 and 14 have been shown as being connected thereto at the same ends of the latter to which the supply valves 16 are connected.

While the improved trap or return fitting has been shown and described as being embodied in a vapor or low-pressure steam heating system, it will be appreciated that the invention is of much broader adaptation and may be used in other connections as well. Furthermore, various changes may be made, such as in the size, shape and arrangement of the parts without departing from the spirit of the invention or the scope of the claims.

The invention claimed is l. A trap of the character described having an inlet opening and an outlet opening and a. well for condensate interposed between said openings, of means providing a vapor passage substantially within said well, one end of said passage being open and arranged to receive vapor flowing into said trap by way of said inlet opening, the other end of said passage being open to permit flow of such vapor through said passage.

2. The combination with a trap of the character described having an inlet opening for connection with a radiator, an outlet opening for connection witha boiler-return line, and a well for condensate interposed between said openings; of means disposed interiorly of said trap and providing a passage extending into said well, one end of said passage being arranged to receive vapor issuing from the radiator into the inlet opening of said trap, the other end of said passage being arranged to discharge such vapor into the boiler-return line.

3. The combination with a trap of the character described having an inlet opening for connection with aradiator, an outlet opening for connection with a boiler-return line, and a well interposed between said openings; of means providing a vapor passage partitioned from and disposed substantially coextensive with said well, one end of said passage being open and arranged to receive vapor issuing from the radiator and flowing into said trap by way of the inlet opening thereof, the other end of said passage being open to permit flow of such vapor through said passage and being arranged to discharge such vapor into the boiler-return line by way of the outlet opening of said trap.

4. A trap of the character described having an inlet opening, an air vent, a well disposed between said opening and said vent, and means arranged in heat-conductive relation with respect to the contents of said well and providing a vapor passage between said opening and said vent.

5. A trap of the character described having an inlet opening for connection with a radiator and an outlet opening for connection with a boiler-return line and being provided with a well for condensate, and means disposed in heat-conductive relation with respect to the contents of said well and providing a passage substantially interiorly of the same, one end of said passage being disposed to receive vapor entering said trap by way of said inlet opening, the other end of said passage being disposed to direct such vapor to said outlet opening.

6. A trap of the character described having an inlet opening for connection with a radiator and an outlet opening for connection with a boiler-return line and a well for condensate interposed between said openings, and means providing a vapor passage disposed interiorly of said trap and extending substantiallythrough said well, one end of said passage communicating with said inlet opening, the other end ofsaid passage communicating with saidoutlet opening.

In testimony whereof I aflix my signature.

HAROLD D. GREGORY. 

